2015 release used kernel 3.18, some drivers were lagging[1] so I went back to arch. But the latest 2016.03 release is now on 4.4, I'm about to try. I saw many people saying they were happy using nixos on twitter. It's a paradigm shift that require a good deal of RTFM. Felt like the first time I used linux somehow.

[1] my wifi chip took minutes to initialize due to proprietary blob issues.